鈥?/div>
B
+
1/2 PA21
R5
10K
+28V
APPLICATIONS
鈥?HALF & FULL BRIDGE MOTOR DRIVERS
鈥?AUDIO POWER AMPLIFIER
STEREO 鈥?18W RMS per channel
BRIDGE 鈥?36W RMS per package
鈥?IDEAL FOR SINGLE SUPPLY SYSTEMS
5V 鈥?Peripherals
12V 鈥?Automotive
28V 鈥?Avionic
R6
10K
FIGURE 1: BIDIRECTIONAL SPEED CONTROL FROM
A SINGLE SUPPLY
The amplifiers are especially well-suited for this application.
The extended common mode range allows command inputs
as low as 0V. Its superior output swing abilities let it drive within
2V of supply at an output current of 2A. This means that a
command input that ranges from 0V to 10V will drive a 24V
motor from full scale CCW to full scale CW at up to
鹵2A.
A
single power op amp with an output swing capability of Vs 鈥?
would require
鹵30V
supplies and would be required to swing
48V p-p at twice the speed to deliver an equivalent drive.
DESCRIPTION
The amplifiers consist of a monolithic dual power op amp
in a 8-pin hermetic TO-3 package (PA21 and PA25) and a 12-
pin SIP package (PA26). Putting two power op amps in one
package and on one die results in an extremely cost effective
solution for applications requiring multiple amplifiers per
board or bridge mode configurations.
The wide common mode input range includes the negative
rail, facilitating single supply applications. It is possible to
have a 鈥済round based鈥?input driving a single supply amplifier
with ground acting as the 鈥渟econd鈥?or 鈥渂ottom鈥?supply of the
amplifier.
The output stages are also well protected. They possess
internal current limit circuits. While the device is well pro-
tected, the Safe Operating Area (SOA) curve must be ob-
served. Proper heatsinking is required for maximum reliabil-
ity.
This hybrid integrated circuit utilizes thick film (cermet)
resistors, ceramic capacitors and semiconductor chips to
maximize reliability, minimize size and give top performance.
Ultrasonically bonded aluminum wires provide reliable inter-
connections at all operating temperatures. The 8-pin TO-3
package is hermetically sealed and electrically isolated. The
use of compressible isolation washers voids the warranty.
The tab of the SIP12 plastic package is tied to 鈥揤
S
.
EXTERNAL CONNECTIONS
PA26
Connect pins
3 and 10 to pin 7
and connect pins
4 and 9 to pin 6
unless special
functions are re-
quired.
1
2
+
A
鈥?/div>
B
SUB
+
鈥?/div>
3
4
5
6
7
8
9
10
11
12
+IN A
鈥揑N A
鈥揑N B
+V
S
2
OUT A
I
SENSE
/鈥揤
S
OUT B
V
BOOST
/+V
S
SENSE
/鈥揤
S
TYPICAL APPLICATION
R1 and R2 set up amplifier A in a non-inverting gain of 2.8.
Amp B is set up as a unity gain inverter driven from the output
of amp A. Note that amp B inverts signals about the reference
node, which is set at mid-supply (14V) by R5 and R6. When the
command input is 5V, the output of amp A is 14V. Since this is
equal to the reference node voltage, the output of amp B is also
14V, resulting in 0V across the motor. Inputs more positive
than 5V result in motor current flow from left to right (see Figure
1). Inputs less positive than 5V drive the motor in the opposite
direction.
+IN, A
3
鈥揑N, A
4
+V
S
2
V
BOOST
/+V
S
+IN B
OUT, A
1
8
OUT, B
鈥揤
S
+V
S
OUT, B
1
鈥揑N, A
4
3
A
鈥?/div>
+
+IN, A
B
+
鈥?/div>
A
5
OUT, A
TOP VIEW
B
8
鈥揑N, B
5
+IN, B
鈥揑N, B
6
鈥揤
S
6
PA25
7
+IN, B
PA21
7
鈥揤
S
APEX MICROTECHNOLOGY CORPORATION
鈥?TELEPHONE (520) 690-8600 鈥?FAX (520) 888-3329 鈥?ORDERS (520) 690-8601 鈥?EMAIL prodlit@apexmicrotech.com
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